Cured bodies obtained by curing conventional curable resin compositions, such as curable epoxy resin compositions, etc., used for sealing and bonding parts of electrical and electronic devices are characterized by a high modulus of elasticity and therefore by high rigidity. Therefore, the use of such bodies in conjunction with electrical or electronic devices is associated with problems such as development of high stress, which develops under conditions of thermal expansion. Another problem associated with the use of cured bodies of the aforementioned compositions is buckling of the electrical or electronic devices or substrates and formation of cracks in the body of the cured resin or gaps in the interface between the cured resin and the electrical or electronic device, which in some cases may lead to destruction of the respective devices.
In order to reduce stress that may develop in the aforementioned cured bodies, it was suggested to prepare a curable silicone composition from an epoxy-containing organopolysiloxane and a curing agent for organopolysiloxane resin (see Japanese Unexamined Patent Application Publications (hereinafter referred to as “Kokai”) H05-105758, 2005-154766, 2006-306953 and 2006-306954). However, when such curable silicone compositions are used for bonding parts of electrical or electronic devices, the problem of oil bleeding of some components of the composition to the outer surface of the cured bodies occurs during curing, and this contaminates the devices.
It is an object of the present invention to provide a curable silicone composition that is characterized by excellent handleability and reduced oil-bleeding during curing, and that, when cured, forms a cured body of excellent flexibility and adhesion.